You can import XML files that were exported using Excel, or standard i18n hierarchical YML files. Both will be normalized as I18nKit::Document objects so that they can be compared with each other. You need implement the comparison method yourself, however. I18nKit only provides the Iterator. )
Gemfile gem 'i18n_kit', '~> 0.0.2'
install gem install i18n_kit -v 0.0.2